TIME-RESOLVED TRANSIENTS OF IR-STIMULATED LUMINESCENCE AND CONDUCTIVITY IN A-SI-H

The transients of IR-stimulated luminescence (ISLT) and conductivity ( ISCT) caused by the excitation of carriers trapped in deep tail states are used for studying the relaxation and recombination processes of n on-equilibrium carriers in a-Si:H. The time behaviour of the transient s is studied in dependence on various parameters (delay time, temperat ure, IR-photon flux). It reveals to be decisively determined by the re peated IR-excitation of the carriers. The quantitative description of the ISCT is based on a model taking into consideration the carrier wai ting time at metastable trapping states in competition with their reco mbination and IR-reexcitation. The mean number of optical reexcitation and the density of deep trapped carriers have been determined as a fu nction of the mentioned parameters.